The 48-Line Volatile URL Shortener

urlshortener.groovy

import java.net.ServerSocket
def socket = 8281, password = "danrulz"
enum Database {
   INSTANCE;
   def table = [:]
   def shortCodeTable = [:]
   def insert = { String url ->
       Sequence.INSTANCE.counter++
       def id = Sequence.INSTANCE.counter
       def shortCode = new BigInteger(id).toString(36)+BigInteger.valueOf(Math.round(Math.random()*1000)).toString(36)
       table.put(id, [url: url, shortCode: shortCode]);
       shortCodeTable.put(shortCode, id)
       return id
   }
   def load = { id -> table.get(id) }
   def findUrlByShortUrl = { uri ->
       return load(shortCodeTable.get(uri))?.url
   }
}
enum Sequence {
   INSTANCE;
   def counter = 1000
}
def server = new ServerSocket(socket), running = true
while(running) {
   server.accept { s ->
      s.withStreams { i, o ->
         def r = i.newReader()
         def b = r.readLine()
         if (b.startsWith("GET")) {
            def m = b =~ /^GET \/(.*) HTTP\/1\.1/
            def uri = m[0][1]
            def url = Database.INSTANCE.findUrlByShortUrl(uri)
            o << "HTTP/1.1 301 Moved Permenantly\nLocation: $url\n\n"
         } else if (b.startsWith("UPDATE")) {
            def m = b =~ /^UPDATE (.*) HTTP\/1\.1/
            def id = Database.INSTANCE.insert(m[0][1])
            def shortCode = Database.INSTANCE.load(id)?.shortCode
            o << "{ \"code\": \"$shortCode\" }\n\n"
         } else if (b.startsWith("PATCH")) {
            def m = b =~ /^PATCH (.*) HTTP\/1\.1/
            if (password.equals(m[0][1])) {
               running = false
            }
         }
      }
   }
}

Add URLs to the database using the HTTP UPDATE METHOD!!

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$ telnet localhost 8281
Trying ::1...
Connected to localhost.
Escape character is '^]'.
UPDATE http://www.yetanothercrappybloghostingprovider.com/really/long/blog/posting HTTP/1.1
{ "code": "rt3c" }

Connection closed by foreign host.

Get redirected with standard HTTP forward codes!!

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[ddcdwoods@mbp-ddcdwoods /]$ telnet localhost 8281
Trying ::1...
Connected to localhost.
Escape character is '^]'.
GET /rt3c HTTP/1.1
HTTP/1.1 301 Moved Permanently
Location: http://www.yetanothercrappybloghostingprovider.com/really/long/blog/posting

Connection closed by foreign host.

Open your browser and notice redirection working!!

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http://localhost:8281/rt3c --> http://www.yetanothercrappybloghostingprovider.com/really/long/blog/posting

AMAZING!!!

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g: daniel.p.woods@gmail.com ... t: @danveloper